Thanks for the advice. I've decided to rehome June and I posted some ads online today. After hours of correspondence with various interested parties, my mom phones, asks why I'm upset and says they'll take her. They already have four Yorkies, but like her fiance said "What's one more?"
This way I don't have to say goodbye and I'll be able to see her whenever I go to visit. She's going home with them after their wedding next weekend. I couldn't be happier with how things have turned out.